The present invention relates generally to antennas, and more particularly, to an improved broadband omnidirectional, vertically polarized communications antenna system.
There are applications where it is desired to have a vertically polarized antenna that provides a circular horizontal plane pattern and a highly directional vertical plane pattern having a single principal lobe directed at the horizon. Broadband omnidirectional, vertically polarized communications antennas of the type similar to the present invention are very widely used throughout the world, and many different designs exist. Many antenna designers have worked out ways to feed the radiating elements. U.S. Pat. No. 4,186,403, entitled “Antenna formed of non-uniform series connected sections” issued Jan. 29, 1980 to Arthur Dorne, provides general background relating to omnidirectional, vertically polarized antennas.
This type of antenna is useful to the military, for example, to enhance communication data rates for Armed Forces radios. The present invention provides for a solution to the need for an improved high bandwidth radio antenna that has not heretofore been available.
No conventional antenna provides for a very broadband, slender, omnidirectional, vertically polarized antenna that is capable of handling reasonably large CW RF power, has good omnidirectionality, has its main beam on the horizon at all frequencies, has enhanced coverage in the upper hemisphere, and has low internal losses. The principal problem has been a limited frequency bandwidth. It would therefore be desirable to have a broadband omnidirectional, vertically polarized communications antenna that provides for all of these capabilities, and in particular has improved bandwidth. Conventional broadband, omnidirectional, vertically polarized antennas have not achieved the wide bandwidth provided by the present invention.